81790147 has 2 divisors, whose sum is σ = 81790148. Its totient is φ = 81790146.

The previous prime is 81790133. The next prime is 81790151. The reversal of 81790147 is 74109718.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81790147 - 2²³ = 73401539 is a prime.

It is not a weakly prime, because it can be changed into another prime (81790127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40895073 + 40895074.

It is an arithmetic number, because the mean of its divisors is an integer number (40895074).

Almost surely, 2^81790147 is an apocalyptic number.

81790147 is a deficient number, since it is larger than the sum of its proper divisors (1).

81790147 is an equidigital number, since it uses as much as digits as its factorization.

81790147 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 81790147 is about 9043.7905216784. The cubic root of 81790147 is about 434.0772212115.

The spelling of 81790147 in words is "eighty-one million, seven hundred ninety thousand, one hundred forty-seven".